Preparing polyester polyols

Abstract

A process for preparing a polyester polyol comprises the steps of: (a) preparing a reaction mixture comprising the following components: A: at least one carboxylic acid recovered from natural raw materials and having at least two acid groups, B: at least one polyhydric alcohol, C: at least one organic phosphite compound, D: at least one Lewis acid; (b) heating the reaction mixture to a temperature of at least 160° C. and removing the water formed in the course of the reaction; (c) heating the reaction mixture to a temperature of at least 210° C. under a pressure below 1013 mbar for a period of time in the range from 0.1 to 25 hours.

1 . A process for preparing a polyester polyol, the process comprising of:
 (a) preparing a reaction mixture comprising:
 A: at least one carboxylic acid recovered from a natural raw material and having at least two acid groups, selected from the group consisting of sebacic acid, azelaic acid, dodecanedioic acid and succinic acid, 
 B: at least one polyhydric alcohol, 
 C: at least one organic phosphite compound, 
 D: at least one Lewis acid; 
   (b) heating the reaction mixture to a temperature of at least 160° C. and removing water formed during a reaction; and   (c) heating the reaction mixture to a temperature of at least 210° C. at a pressure below 1013 mbar for 0.1 to 25 hours,   to obtain a polyester polyol.   
     
     
         2 . The process of  claim 1  wherein (a) comprises first mixing A, B and D, and then adding C. 
     
     
         3 . (canceled) 
     
     
         4 . The process of  claim 1 , wherein A comprises sebacic acid recovered from a renewable raw material. 
     
     
         5 . The process of  claim 1 , wherein B comprises an aliphatic C 2  to C 6  diol. 
     
     
         6 . The process of  claim 1 , wherein B comprises 1,3-propanediol or 1,4-butanediol. 
     
     
         7 . The process of  claim 1 , wherein C comprises at least one organic phosphite compound selected from the group consisting of bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, tris(nonylphenyl)phosphite or a reaction product of phosphorus trichloride with 1,1′-biphenyl and 2,4-bis(tert-butyl)phenol. 
     
     
         8 . The polyester polyol obtained by the process of  claim 1 . 
     
     
         9 . The polyester polyol of  claim 8  wherein A comprises sebacic acid recovered from a renewable raw material, and B comprises a diol. 
     
     
         10 . A process for preparing a polyurethane by reacting the polyester polyol obtained by the process  claim 1  with one or more organic diisocyanates. 
     
     
         11 . A thermoplastic polyurethane obtained by the process of  claim 10 . 
     
     
         12 . (canceled) 
     
     
         13 . A process of manufacturing a molding, a hose, a self-supporting film/sheet, or a fiber, the process comprising the process of  claim 10 . 
     
     
         14 . A molding, a self-supporting film/sheet, a hose or a fiber comprising the thermoplastic polyurethane of  claim 11 . 
     
     
         15 . The process of  claim 1 , wherein (c) is performed for 5 to 20 hours. 
     
     
         16 . The process of  claim 1 , wherein B comprises 1,3-propanediol. 
     
     
         17 . The process of  claim 1 , wherein B comprises 1,4-butanediol. 
     
     
         18 . The process of  claim 1 , wherein D is selected from the group consisting of titanium tetrabutoxide, titanium tetraisopropoxide, tin dioctoate, dibutyltin laurate, and tin chloride. 
     
     
         19 . The process of  claim 1 , wherein the polyester polyol obtained has a color number between 10 and 200 APHA/HAZEN. 
     
     
         20 . The process of  claim 1 , wherein the polyester polyol obtained has an acid number less than 3 g KOH/kg. 
     
     
         21 . The process of  claim 1 , wherein the polyester polyol obtained has an acid number less than 1 g KOH/kg. 
     
     
         22 . The process of  claim 1 , performed without a solvent.